How to work with MongoDB in .Net

Get started with documents and collections in the popular, open source, NoSQL database using C#

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MongoDB is a popular, open source, scale-out NoSQL database that provides high throughput for your data-driven applications. Unlike relational databases such as SQL Server, Oracle, and MySQL, which store data in tables according to a rigid schema, MongoDB stores data in documents with flexible schema. There are many such non-relational databases around including CouchDB, RavenDB, and Couchbase. However, I like MongoDB primarily due to its scalability, speed, and dynamic querying capabilities.

MongoDB uses the BSON format under the hood to represent the JSON documents at the heart of the data store. BSON or “Binary JSON” is a lightweight and efficient binary-encoded data serialization format that supports fast data traversal and searches. BSON also allows MongoDB to support data types—namely int, long, date, floating point, and decimal128—not represented in JSON.

In MongoDB documents are part of collections, in much the same way as a row is part of a table in a relational database. A document is essentially a collection of field and value pairs, which can also be nested. Note that a value in MongoDB can be a document, an array of documents, an array of BSON, or just a BSON type. Let’s look at how we can work with MongoDB using C#.

Install MongoDB and create a new project

Start by downloading the MongoDB binaries. Unzip the binaries to a folder of your choice in your system and create a separate folder (in my case C:\data\db) for the data. Then, to start MongoDB, navigate to the folder where MongoDB is installed and execute the mongod command in the command prompt window. That should start MongoDB at port 27017 by default.

Create a new console application project in Visual Studio and install the MongoDB.Driver package via the NuGet Package Manager Console with the following command.

The BsonDocument class in the MongoDB.Bson package is used to represent a BSON document. The following code snippet shows how you can display the names of the databases available in the instance of MongoDB running in your system.

When you execute the above code snippet, you will see the name of the database (i.e., “IDG”) listed in the console window. You can also use the asynchronous method, ListDatabasesAsync, to list the database names, as shown in the code snippet given below.

MongoDB is a popular NoSQL database that has a flexible data model and scales gracefully. MongoDB provides support for horizontal scalability using a technique known as sharding. I will discuss more advanced concepts in MongoDB in future posts here. Until then, you may want to read up on the MongoDB C# driver in the MongoDB documentation.

Joydip Kanjilal is a Microsoft MVP in ASP.Net, as well as a speaker and author of several books and articles. He has more than 20 years of experience in IT including more than 16 years in Microsoft .Net and related technologies.